Portable crane



June 26, 195] G. H. HUBBARD PORTABLE CRANE 7 Sheets-Sheet 1 Filed Sept. 24, 1948 6501-26: H. HUBBARD Zhwemor June 26, 1951 Filed Sept. 24; 1948 G. H. HUBBARD PORTABLE CRANE '7 Sheets-Sheet 2 H BARB (Ittorneg June 26, 1951 HUBBARD 2,558,686

PORTABLE CRANE Filed Sept. 24, 1948 7 Sheets-Sheet 3 Snventor 650505 H. HUBBARD June 26, 295] G. H. HUBBARD 2,553,686

PORTABLE CRANE Filed Sept, 24, 1948 .7 Sheets-Sheet 4 GEO/26E H. HUBBARD ISnnenlor (Ittorneg June 26, 1951 G. H. HUBBARD 2 ,686

PORTABLE CRANE Filed Sept. 24, 1948 7 Sheets-Sheet 5 49 70 I fi I "I Kg.

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650E615 Hussnao 3nvemor Gttomeg June 26, 195'] HUBBARD 2,558,685

PORTABLE CRANE Filed Sept. 24, 1948 7 Sheets-Sheet 6 65012 as H. Hussy/a0 3nventor Gttomeg G. H. HUBBARD PORTABLE CRANE June 26, 1951 Filed Sept. 24, 1948 i E 49 L 50 o O Q f- 7 Sheets-Sheet '7 Smaentor 650R 65 H. Ht/B5 (Ittorneg Patented June 26,4951

" STATES PATENT FICE PORTABLE CRANE George H. Hubbard, Seattle, Wash., assignor to Washington Iron Works, Seattle, Wash, a corporation of Washington 12 Claims.

This invention relates to portable cranes, and especially pertains to a crane of this nature relying for its portability upon a tractor or other like vehicle which is so attached to the tractor as to enable the crane to use the power of the tractor's engine for its operation while at the same time permitting the tractor to be disassociated from the crane and employed independently of the crane for the performance of other useful work. The present invention is an improvement over the structure illustrated and described in pending application of Jack I. Morgan and Burton B. Chisholm filed April 6, 1948, Ser. No. 19,318.

The crane of the present invention is one in which all of the mechanism responsible for the activation of the crane, lacking only the prime mover, are mounted upon an elevated platform, and in which this platform is supported for rotary slewing movements by a stand arranged and adapted to straddle the tractor. The power of the prime mover, and which is to say the power of the tractors engine, is passed upwardly to the platform, and it is an important feature of the present invention to provide a perfected means of attaining this end peculiarized in that the power transfer in no way interferes with the slewing movements and permits the platform to turn through a full 360 of rotation.

Another feature of the invention resides in the provision of a perfected stand which operates, during working of the crane, to give maximum stability to the latter by establishing firm ground footings to the front and at each side and which, over and above the stability given to the crane, entirely relieves the tractor of any part of the weight load of the crane.

The foregoing, with other and more particular features of the invention, and the advantages arising therefrom, will appear and be understood in the course of the following description taken in connection with the accompanying drawings, in which Figure 1 is a side elevational view portraying a portable crane constructed to embody the teachings of the present invention, this view illustrating the tractor in the position which it occupies when the crane is being worked. Fig. 2 is an enlarged front elevational view thereof with the casing which houses the craneactivating mechanism broken away, and also with the control lines which lead from the operators cab of the crane to the lower-level tractor shown only fragmentarily. I

Fig. 3 is a fragmentary horizontal sectional view to a yet larger scale taken through the operators cab and with the referred-to casing deleted, one of the cable-winding drums being broken away to show the power gear which receives its drive from the power plant of the tractor. This view deletes any showing of the several gear trains driven off said power gear and which are carried by the platform on a level below that occupied by the drums.

Fig. 4 is a fragmentary plan view looking down upon the several gear trains, the scale being here again enlarged from that employed in Fig. 3.

Figs. 5 and 6 are a fragmentary transverse vertical section and a fragmentary longitudinal vertical section taken to an enlarged scale on lines 55 and 6-6, respectively, of Fig. 4.

Fig. '7 is a fragmentary side elevational view detailing one of the two rest-blocks which establish side footings for the crane-supporting stand.

Fig. 8 is a transverse vertical section on line 88 of Fig. "I.

Fig. 9 is a view similar to Fig. '1 but showing a modified structure in which the rest-block embodies a jack mechanism.

Fig. 10 is a transverse vertical section on line I0-l0 of Fig. 9; and

Fig. 11 is a fragmentary plan view portraying, somewhat schematically, the drum-handled block-and-tackle take-up by which the boomarms topping line is controlled.

Before proceeding with a detailed description of those features of the present invention which I deem to be novel, it may be here stated that the operator of the crane occupies a position upon an elevated platform which is made to turn with the boom-arm about a perpendicular axis. This boom-arm, designated by the numeral l2, operates much in the ordinary manner, being pivotally attached at its root end to the platform and having a topping lift 13 working through a block-and-tackle connection from a topping line It to control the elevation of the free end, and being also terminally fitted with the usual block to handle the loading line l5. There is carried upon the platform a severalty of cable-winding drums for the said lines, and these drums, with their necessary brakes and clutches, are or may be of ordinary or suitable construction and derive the energy responsible for their operation from gear trains driven off a bevel gear l6 common to each. This bevel gear is journal-mounted from the platform for rotary movement about a perpendicular axis and through connections hereinafter to be described receives its power from the associated tractor, denoted by the letter T, which occupies a position below the platform.

Said bevel gear hence becomes the power gear and will be hereinafter so termed. Mounted upon the platform is an air compressor driven on! said bevel gear, and a pressure-air reservoir supplied by the compressor, and there is provided an operator's cab il equipped with multiple controls It and ill working through pressure air suppliedfrom the reservoir to govern the operation of the several brakes and clutches. In addition to the controls 18 and It. the cab presents pressure-air controls denoted 23 and 2|. working through connections which also will be hereinafter described, as a remote means of governing the operation of the tractors engine, and this is to say that one such remote control regulates the throttle and the other a clutch functional to bring the engine into operating couple with a power take-off (hereinafter described) which leads to said power gear It.

The platform, designated by 23, is supported for slewing movements upon a stand and, as is usual for this purpose, provides rollers 22 bearing upon an annular track which is rigid with the stand, and to obtain these slewing movements there is provided at the head end of the stand the usual bull gear 23 which is meshed by a spur pinion 24, the spur pinion being keyed to a vertical stub shaft 25 on the upper end of which is carried a bevel gear 26, the bevel gear being in constant mesh with a pair of diametrically oppositely placed bevel gears 21 taking their power through a train of gears driven from the power gear i6 and being selectively activated, a with the cable-winding drums, by clutch and brake mechanisms controlled by presure air from the operator's cab, all of which will be well understood. Reverting now to a description of the stand, the same is fabricated at the top from a pair of laterally spaced side beams 30 connected across the ends by girder members 3i. Each of said side beams, and as can be best seen in Fig. 1, constitutes the upper chord of a truss, and whose lower chord member 32 is connected thereto by front and rear legs 33 and 34. At the rear end of the stand, the two legs are unattached at their lower ends, but at the front end there is provided a cross-tie 35 of comparatively wide fore-and-aft dimension which operates to bear upon the ground and perform the ofilce of a stabilizing shoe, this shoe presenting a dependency 36 arranged and adapted by its' penetration of the ground to establish a toe-hold for the shoe. Said lower chords 32 of the respective side trusses incline upwardly from front to rear, and aside from stiffening the framework this inclination operates to place the lower end of back legs well above the plane occupied by the shoe 35. As suporting mounts for these back legs there is provided, for each, a rest-block. In the form in which these rest-blocks are illustrated in Figs. 1 and 2. and detailed in Figs. 7 and 8, the same are each comprised simply of a vertical plate 31 pivotally attached, as at 38, to the bottom end of the related leg and presenting a footing flange 39 rigidified by reinforcing ribs 4|]. The purpose in pivotally mounting the block is to enable the same to be swung upwardly into an out-of-theway position whereat the same rests upon a legcarried lug 49, this position being occupied only when the crane is being moved fromone to another location. In using the described restblocks, it is to be understood that compensation for uneven ground is made by inserting planks or the like under one or both blocks, but it is 4 self-evident that the blocks themselves can be made adjustable for height through the instrumentality of'incorporating a screw or hydraulic Jack structure in the block. To exemplify a structure of this nature I have detailed'inFigs. 9 and 10 a Jack comprised of a piston 4| working in a cylinder 42, and having a footing piece 43 carried by a ball-and-socket joint upon the exposed lower end of the piston. The cylinder is pivotally attached, as at 44, to the related leg, and pressure fluid for the operation of the jack is supplied from the pressure-air reservoir of the crane, the hose 4! therefor incorporating a control valve 40.

The tractor which I have elected to illustrate is of the crawler type and need not be particularly described other than to point out that the same is provided at its rear end with a winch 41 and a power take-oi! shaft (not shown), and also provides means upon each of its two sides permitting the tractor to be detachably anchored to the rear legs of the stand. Where the tractor is equipped with a bull-dozer blade, this anchoring attachment may be advantageously accomplished by connecting the rear legs with the vertically swingable side arms it which support the dozer blade, and to exemplify structure for this purpose I have shown two embodiments, one as it is applied to a stand fitted with the non-ad- ,iustable rest-blocks and the other as applied to a stand fitted with the vertically adjustable rest-blocks. In the former said structure, there is bolted upon each of the two side arms a respective block 5i formed with an upstanding apertured ear 52, and this ear is made to fit in a bottom recess of the back leg. The pivot pins 38 traverse these recesses and pass through the aperture of the ears. The free the tractor, the bolts are removed. In the other said embodiment, the mounting is modified to the extent that the upstanding ear overlies the inner side wall of the related rear leg and employs, as a detachable coupling, a pin 53 offset from the pivot pin 38.

It may be here pointed out that a rest-block embodying a Jack mechanism is of particular advantage in that it makes the rest-blocks selfsuillcient for accomplishing elevational movements, and by such token would, if desired, permit the rear legs to be detachably anchored to trunnion pins integrated with the frame of the tractor, using for this purpose removable saddling caps. The salient point is that the jack rather than the dozer-carrying side arms could be employed to lower the rest-blocks in the degree necessary to bring the same into bearingengagement upon the ground surface when takigg the weightof the crane off the anchor mountgs. r

The tractor, when it occupies the coupled position in which it is shown in Figs. 1 and 2, locates the power take-off shaft such as to be in approximate alignment with and axially spaced from a stub pick-up shaft which is journalmounted at the lower end of a transfer case 54 carried by the frame-work of the stand. Detachable connection is then made between the two shafts by means of a drive rod 56. The'connections from the drive rod to the two shafts. and namely to the power take-oil shaft and to the stub pick-up shaft, embodies universal joints generally denoted by I! and 58. One element of these joints is or may be fixedly applied upon the related shaft so as to constitute a permanent tail fitting and I designate these tail fittings 60 to pass the drive upwardly within the case to a complementing sprocket wheel 6|. The latter sprocket wheel powers a horizontal shaft 62 and such shaft, as will be seen from an inspection of Fig. 5, enters a gear box 63 wherein the I same acts through intermeshing bevel gears 64 and 65 to transmit the drive to a vertical shaft 66 having the power gear l6 keyed upon its upper end. Said vertical shaft is made hollow, and received through and projecting beyond the ends thereof are two stationary pipes 61 and 68 received one within the other and characterized in that the inner said pipe has an outside diameter less than the inside diameter of the outer pipe. Connecting top and bottom with the inner such pipe are respective air-flow connections 10 and II leading the one said hose from the upperlevel air compressor and the other said connection to a lower-level cylinder-and-piston unit Hi Similarly, a connection 13 leads from the upperlevel air compressor to the upper end of the other or outer pipe 68, and a connection 14 runs from the lower end of this pipe to a second lower-level cylinder-and-piston unit 15. The connection 10 includes the control '20 and the connection 13 includes the control 2|, both hereinbefore referred to. Each of the several connections 10, H, 13 and H are, in practice, desirably comprised of flexible hose, and the'cylinder-and-piston units to which the same lead are, with complementing connecting rods 16 and H, removably associated with the tractor. The rod 16 connects with the tractors clutch-operating lever 80 and the rod 11 connectswith the tractors engine throttle 8|.

From the foregoing, it is thought that the invention and the manner of its employment will have been clearly understood. During operating periods of the crane, the tractor will occupy the position in which it is shown and will be made secure to the framework of the stand by means of its connection with the rear legs 34. Should it be desired to move the crane to a new location, the rest-blocks are each freed of the weight of the crane and swung upwardly into inoperative positions whereat the same are sustained by the lugs 49, and the winch 41 is then energized to elevate the stabilizing shoe 35 out of contact with the ground, the cable 82 of said winch finding its connection with the shoe by means of a clevis or the like 83. The crane may be then moved bodily with the tractor, and upon reaching the new location the stabilizing shoe is again lowered into a position whereat the same will establish a, ground hold and the rest-blocks are swung into operating positions and caused to bear by their footing flanges upon the ground. The tractor is thereby entirely relieved of the weight of the crane, and while taking its power from the engine of the tractor the crane may be controlled entirely from within the platform-carried cab. It is to be particularly noted that the perfected method of passing the drive upwardly through a perpendicularly mounted power shaft placed co-axial to the center of the bull gear and having each of the connections for control of the tractors engine pass through the hollow center of this shaft allows the crane to turn freely through a full 360 of slewing movements.

The tractor may be worked independently of the crane by simply disconnecting the winchcable and the side mountings, and backing the tractor from the crane.

While I have illustrated and herein described an embodiment which I now consider to best exemplify the teachings of the present invention, it is self-evident that minor changes in the details of construction may be resorted to without departing from the spirit of the invention and it is accordingly my intention that the hereto annexed claims be construed to a scope fully commensurate with the broadest interpretation to which the employed language fairly admits.

What I claim is:

1. In combination, a tractor having a power take-off; an elevated platform; a frame-work therefor normally resting upon the ground and supporting the platform for rotational movement about a vertical axis and providing clearance for the unobstructed movement of the tractor into and from a position. below the platform; loadhandling crane structure sustained upon the platform; a releasable connection between the tractor and the platform's supporting framework for localizing the tractor relative to said frame-work when the tractor occupies a position below the platform arranged and adapted to be powered from the power plant of the tractor; a power shaft for passin the power of the power plant upwardly to said crane structure journal-mounted from said frame-work for rotation about an axis coinciding with the rotary axis of the platform; and power-transfer means also carried by the frame-work and adapted to be detachably coupled to said power take-off of the tractor for driving said power shaft.

2. In combination: a tractor having a power take-01f an elevated platform; a stand therefor self-sufficient to sustain the platform and supporting the latter for rotational movement about a vertical axis and also providingclearance for the unobstructed movement of the tractor into and from an operating position below the platform; load-handling crane structure including cable-winding drums and manually-operated controls therefor mounted upon the platform; a power shaft operatively interconnected by its output end with said drums and journal-mounted from said stand for rotation about an axis coinciding with the rotary axis of the platform with its input end projecting below the platform; and means also carried by the stand arranged and adapted when the tractor occupies its said operating position to be detachably connected with the power take-off and acting to transfer the 'power from said take-off to the input end of the power shaft.

3. In combination: a tractor having a power take-off; an elevated platform; a stand therefor self-sufficient to sustain the platform and supporting the latter for rotational movement about a vertical axis and so formed as to provide clearance for the unobstructed movement of the tractor into and from an operating position below the platform; a load-handling boom arm footin upon the platform; operatin mechanism carried by the platform arranged to be powered from the power plant of the tractor and manually controlled from a position upon the platform for working the boom arm and also performing e ing movements of the platform; a power shaft operatively interconnected by its output end with said operating mechanism and receiving a journal-mounting from the stand to support the same for rotation about an axi coinciding with the rotary axis of the platform, the input end of said power shaft projecting below the platform; means also carried by the stand arranged and adapted when the tractor occupies its said operating position to be detachablgyconnegted with the power take-off and acting to transfer the power from said take-oil to the input end of the power shaft, said tractor being provided with a throttle for governing the speed of the power plant and also having a clutch by which the power take-off it activated and inactivated at will; and means remotely controlled from a position upon the platform for regulating said throttle and operating the clutch.

4. In combination with a tractor having a power take-off; an elevated platform; a stand therefor. having an inverted-U shape in end ele- 'vation and providing a rotary mounting supporting the platform for slewing movements about a vertical axis and made self-sufficient to establish a firm ground footin while at the same time givin clearance within the throat of the U for the unobstructed movement of the tractor into and from an operating position below the platform; means for detachably anchoring the tractor to the standv to localize the tractor when the latter occupies its said operating position; a load-handling boom arm footing upon the platform; topping and hoist lines for the boom arm; operating mechanism carried by the platform arranged to be powered from the power plant of the tractor and manually controlled from a position upon the platform for working the topping and hoist lines and for performing slewing movements of the platform; power shaft operatively interconnected by its output end with said operating mechanism and receiving a journal-mounting from the stand to support the same for rotation about an axis coinciding with the rotary axis of the platform, the input end of said power shaft projectin below the platform; and means for establishing a driving couple from said power take-off of the tractor to the input end of said power shaft.

5. In combination with a tractor provided at its rear end with a power take-off and a winch; an elevated platform; a stand therefor providing a rotary mounting supporting the platform for slewing movements about a vertical axis and so formed as to establish firm ground footings front and rear while at the same time giving clearance for the unobstructed backing of the tractor into an operating position below the platform, said front footing comprising a stabilizing bar extending the entire width of the stand and said rear footing comprising separate and retractable bearing feet located at the side limits of the stand; mounting means provided at each side of the tractor and arranged to detach ably engage the stand at points adjacent said bearing feet and serving to localize the tractor when the. latter occupies its said operating position; a load-handlin boom arm hinged for vertical swinging movements to the platform; topping and hoist lines for the boom arm; operating mechanism carried by the platform arranged to be powered from the power plant of the tractor and manually controlled from a position upon the platform for working the topping and hoist lines and for performing slewing movements of the platform; a power shaft operatively interconnected by its output end with said operating mechanism and receiving a, journal mounting from the stand to support the same for rotation about an axis coinciding with the rotary axis of the platform, the input end of said power shaft projecting below the platform; and means for establishing a driving couple from said power take-oif of the tractor to the input end of said power shaft; and a cable extending downwardly from the winch and connecting with the front ground footings for raising the latter off the ground and when performed in conjunction with a retraction of the bearing feet acting with the mounting means to cause the entire weight of the stand and its surmounting platform to be sustained by the tractor and thus allowing said stand and its surmounting platform to be moved bodily with the tractor.

6. In combination with a tractor provided with a power take-off and also having a winch at its rear end; an elevated platform supporting a load-handling crane and also carrying mechanism for the operation ofthe crane arranged and adapted to be powered from the power plant of the tractor; a, stand for the platform supporting the latter for slewing movements about a vertical axis and so formed'as to establish firm ground tending downwardly from the winch and connecting with the front ground footings for raising the latter off the ground and when performed in conjunction with a retraction of the bearing feet acting with the mountin means to cause the entire weight of the stand and its surmounting platform to be sustained bythe tractor and thus allowing said stand and its surmounting platform to be moved bodily with the tractor.

7; The combination of claim 6 in which the retractable bearing feet are each comprised of a jack structure with the jacks being operated by pressure fluid, and in which the source of supply therefor is carried upon the platform and the pressure of the fluid developed by power derived from the power plant of the tractor.

8. Structure according to claim 6 in which the tractor is equipped with a dozer blade supported by side arms swingably mounted from the tractor and energized by the power plant of the latter, the mounting means being supported upon said side arms.

9. Structure according to claim 8 in which the bearing feet are pivotally connected with the stand to enable the feet to be retracted through the act of swinging the same upwardly into an out-of-the-way position when it is desired to move the stand and its supported platform bodily with the tractor.

10. In combination with a tractor provided at its rear end with a winch; an elevated platform supporting a load-handling crane and also carryin mechanism for the operation of the crane; a stand therefor providing a rotary mounting supporting the platform for slewing movements about a vertical axis and so formed a to establish firm ground footings front and rear while at the same time giving clearance for the unobstructed backing of the tractor into position below the platform, said rear ground footings comprising retractable bearing feet located at the side limits of the stand; and mounting means provided at each side of the tractor and arranged to detachably engage the stand at points adjacent said bearingfeet; and a cable extending forwardly from the winch and connecting with the front ground footings for raising the latter off the ground and when performed in conjunction with a retraction of the bearing feet actin with the mounting means to cause the entire weight of the stand and its surmounting platform to be sustained by the tractor and thus allowing said stand and its surmounting platform to be moved bodily with the tractor.

11. In combination with a tractor; an elevated platform supporting a load-handling crane and also carrying mechanism for the operation of the crane; a stand therefor providing a rotary mounting supporting the platform for slewing movements about a vertical. axis and so formed as to establish firm ground footings front and rear while at the same time giving clearance for the unobstructed backing of the tractor into position below the platform, said rear ground footings comprising retractable bearing feet located at the side limits of the stand; and mounting means provided at each side of the tractor and arranged to detachably engage the stand at points adjacent said bearing feet, means being provided by the tractor for lifting and suspending the front end of the stand to elevate said front end off the ground and when performed in conjunction with a retraction of the bearing feet acting with the mountin means to cause the entire weight of the stand and its surmounting platform to be sustained by the tractor and thus allowing said stand and its surmounting platform to be moved bodily with the tractor.

10 12. In combination with a tractor; an elevated platform supporting a load-handling crane and also carrying mechanism for the operation of the crane; and a stand for the platform formed to establish firm ground footings front and rear while at the same time givin clearance for the unobstructed movement of-the tractor into a position below the platform, said front footing comprising a transversely extending bar member integrated with the stand and presenting a depending vertical flange running coextensive of the length of the bar and arranged to dig into the ground for establishing a stabilizing grip; means bein provided by the tractor arranged to engage, raise and suspend the stand with its said front and rear footings both out of contact with the ground whereby to permit the stand and its surmounting platform to be moved bodily with the tractor.

G. H. HUBBARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,564,133 Fraser Dec. 1, 1925 1,909,528 Garson May 16, 1933 2,162,994 Baker June 20, 1939 2,362,220 Shoemaker Nov. 7, 1944 2,365,169 Billings Dec. 19, 1944 2,366,115 Kuch et al Dec. 26, 1944 2,446,220 Erdahl Aug. 3, 1948 

